1. Field of the Invention
The present invention relates to a method for manufacturing of an organic light emitting display device, and more particularly, to a method for manufacturing of an organic light emitting display device applicable to high resolution and a large area.
2. Discussion of the Related Art
As a type of new flat panel display device, organic light emitting display devices including organic light emitting diodes (OLEDs) are self-emitting display devices, and have a better viewing angle and contrast ratio than liquid crystal display (LCD) devices. Also, since the organic light emitting display devices do not need a separate backlight, it is possible to lighten and thin the organic light emitting display devices, and the organic light emitting display devices have excellent power consumption compared to LCD devices and the other flat panel display devices. Furthermore, the organic light emitting display devices are driven with a low direct current (DC) voltage, have a fast response time, and are low in manufacturing cost.
In the organic light emitting display devices, a fine metal mask (FMM) process, an inkjet process, a lift-off process, or the like is used for patterning an emission layer between two electrodes disposed on a substrate.
However, due to limitations of mask manufacturing technology, it is difficult to apply the FMM process to a large size and high resolution. That is, when the organic light emitting display device is applied to a large area, a mask sags due to the weight thereof, and thus, it is difficult to form a desired pattern. Also, the spread of organic materials increases due to a separated distance between the mask and a deposition portion, and therefore, it is difficult to realize high resolution. Furthermore, since the inkjet process needs to use a liquid material, the performance of an OLED exposed by a process is degraded. Especially, in the existing methods including an etching process, a disconnection occurs by direct contact between metal and etching solutions, or it is not easy to control an etching depth, causing the decrease in device characteristic.
Also, the lift-off process includes only an exposure operation and a development operation except an etching operation among operations included in a photo masking process, thereby enabling formation of a fine pattern. However, the defect of an emission layer is caused by a used solvent and a residual layer that is formed by strong adhesive strength in an operation of removing a photoresist pattern, and therefore, the lift-off process still degrades the efficient characteristic of a display device.